Photoresist having increased sensitivity and use thereof

Abstract

The sensitivity of a photoresist to actinic light is improved by the addition of certain dyes. The photoresist includes a polymer matrix, a photosensitive acid generator and at least one compound selected from the group consisting of dyes containing at least one heterosulphur atom such as 2,2 1 ,5 1 ,2"-terthiophene and its derivatives; thianthrene and its derivatives, and 4,6-diphenylthieno(3,4-d)-1,3-dioxol-2-one-5,5-dioxide; phenylsulfone and its derivatives; and 4,5-diphenyl-1,3-dioxol-2-one; 3,4-bis(acetoxymethyl)furan; chelidonic acid and its derivatives; and 5,7,12,14-pentacenetetrone. Resist images on a substrate are formed from the compositions.

What is claimed is: 
     
       1. A positive photoresist having increased sensitivity comprising: a polymer matrix,   a photosensitive acid generator wherein said acid generator is an onium salt, and   at least one compound selected from the group consisting of phenylsulfone, and derivatives thereof having the formula: ##STR24##   
     
     
        4. 5-diphenyl-1,3-dioxol-2-one; thianthrene and its derivatives having the formula: ##STR25## and 4,6-diphenylthieno(3,4-d)-1,3-dioxol-2-one-5,5-dioxide; and wherein R and R' in the above formulae are individually selected from the group of H, alkyl having 1 to 12 carbon atoms, aryl having 6 to 18 carbon atoms, --(CH 2 ) n , --C(--O)--OH, --NO 2 , --OR IV , --OCH 2  CH 2  OR IV  wherein R IV  is H or alkyl having 1 to 12 carbon atoms. 
     
     
       2. The photoresist composition of claim 1 wherein said polymer matrix is selected from the group consisting of novolak resins and copolymers of hydroxystyrene and a member selected from the group consisting of acrylate, methacrylate and mixtures thereof; poly(hydroxystyrene); poly(hydroxystyrene-co-t-butyloxycarbonyloxystyrene); poly(hydroxystyrene-co-hydroxymethylstyrene); poly(hydroxystyrene-co-acetoxymethylstyrene); alkyl substituted polyvinyl phenols; poly (p-tert-butoxy carbonyloxy-a-methylstyrene); poly (p-tert-butoxycarbonyloxystyrene); poly(tert-butyl p-vinylbenzoate); poly (tert-butyl p-isopropanol phenyl oxyacetate); and poly(tert-butyl methacrylate). 
     
     
       3. A method for producing a resist image on a substrate comprising: a) coating the substrate with a positive photoresist having increased sensitivity comprising: a polymer matrix, a photosensitive acid generator, wherein said acid generator is an onium salt, and a compound selected from the group consisting of phenylsulfone and derivatives thereof having the formula: ##STR26##     
     
     
       4. 5-diphenyl-1,3-dioxol-2-one; thianthrene and its derivatives having the formula: ##STR27## and 4,6-diphenylthieno(3,4-d)-1,3-dioxol-2-one-5,5-dioxide; and wherein R and R' in the above formulae are individually selected from the group of H, alkyl having 1 to 12 carbon atoms, aryl having 6 to 18 carbon atoms, --(CH 2 ) n , --C(--O)--OH, --NO 2 , --OR IV , --OCH 2  CH 2  OR IV  wherein R IV  is H or alkyl having 1 to 12 carbon atoms, (b) imagewise exposing the photoresist to actinic light, and   
     
     
       (c) then developing the photoresist to produce the resist image. 4. The method of claim 3 wherein said polymer matrix is selected from the group consisting of novolak resins and copolymers of hydroxystyrene and a member selected from the group consisting of acrylate, methacrylate and mixtures thereof; poly(hydroxystyrene); poly(hydroxystyrene-co-t-butyloxycarbonyloxystyrene); poly(hydroxystyrene-co-hydroxymethylstyrene); poly(hydroxystyrene-co-acetoxymethylstyrene); alkyl substituted polyvinyl phenols; poly (p-tert-butoxy carbonyloxy-a-methylstyrene); poly (p-tert-butoxycarbonyloxystyrene); poly(tert-butyl p-vinylbenzoate); poly (tert-butyl p-isopropenyl phenyloxyacetate); and poly(tert-butyl methacrylate). 
     
     
       5. A positive photoresist having increased sensitivity comprising: a polymer matrix, wherein said polymer matrix comprises a copolymer of hydroxystyrene and a member selected from the group consisting of acrylate, methacrylate and mixtures thereof;   a photosensitive acid generator wherein said acid generator is an onium salt, and   at least one compound selected from the group consisting of dye selected from the group consisting of thianthrene and its derivatives having the formula: ##STR28## phenylsulfone, and derivatives thereof having the formula: ##STR29##     
     
     
        4. 5-diphenyl-1,3-dioxol-2-one and mixtures thereof and wherein R and R' in the above formulae are individually selected from the group of H, alkyl having 1 to 12 carbon atoms, aryl having 6 to 18 carbon atoms, --(CH 2 )n, ##STR30## --NO 2 , --OR IV , --OCH 2  CH 2  OR IV  wherein R IV  is H or alkyl having 1 to 12 carbon atoms. 
     
     
       6. The photoresist of claim 5 wherein said compound is thianthrene or derivative thereof. 
     
     
       7. The photoresist of claim 5 wherein said compound is 4,6-diphenylthieno(3,4-d)-1,3-dioxol-2-one-5,5-dioxide. 
     
     
       8. The photoresist of claim 5 wherein said compound is phenylsulfone or derivative thereof. 
     
     
       9. The photoresist of claim 5 wherein said compound is 4,5-diphenyl-1,3-dioxol-2-one. 
     
     
       10. The photoresist of claim 1 wherein said acid generator is a sulfonium or iodonium salt. 
     
     
       11. The photoresist of claim 5 wherein said onium salt is ##STR31## wherein R=C 10  H 21 . 
     
     
       12. The positive photoresist of claim 5 wherein said polymer matrix comprises copolymer of hydroxystyrene and t-butyl methacrylate. 
     
     
       13. A method for producing a resist image on a substrate comprising: a) coating the substrate with a positive photoresist having increased sensitivity comprising:   a polymer matrix comprising a copolymer of hydroxystyrene and a member selected from the group consisting of acrylate, methacrylate and mixtures thereof, a photosensitive acid generator, wherein said acid generator is an onium salt, and a compound selected from the group consisting of thianthrene, phenylsulfone and mixtures thereof;   b) imagewise exposing the photoresist to actinic light, and   c) then developing the photoresist to produce the resist image.   
     
     
       14. The method of claim 13 wherein said actinic light is deep UV light radiation. 
     
     
       15. The method of claim 13 which further comprises subjecting said composition to elevated temperatures of about 100° C. to about 160° C. between steps b) and c). 
     
     
       16. The method of claim 13 wherein said dye comprises thianthrene. 
     
     
       17. The method of claim 13 wherein said dye comprises polysulfane. 
     
     
       18. The method of claim 13 wherein said polymer matrix comprises a copolymer of hydroxystyrene and t-butyl methacrylate.